播期对直播水稻产量、花后各器官干物质和氮素积累及转运的影响

为探究播期对直播水稻产量、花后干物质和氮素积累与转运的影响,以水稻品种白粳1号、长白9号和龙粳31号为供试材料,设置3个播期（SD1、SD2和SD3）,比较不同播期条件下3个品种的产量、抽穗期和成熟期各器官干物质及氮素积累与转运特点。3个品种抽穗期和成熟期各器官干物质及氮素积累量、抽穗至成熟期各器官干物质及氮素转运量和产量均表现为SD2>SD3>SD1。相关分析表明,产量与成熟期穗干物质及氮素积累量呈显著正相关,与叶片干物质和氮素转运量呈显著正相关。在本试验条件下,播期的推迟提高了3个品种有效穗数及结实率,进而提高了产量,同时促进了各器官物质转运量与转运率的提高。各品种SD2处理的产量及花后干物质、氮素积累量最高,SD2为适宜播期。     

天目山－怀玉山区水源涵养与生物多样性保护 重要区生态承载力评价

为了明确近10年天目山－怀玉山区水源涵养与生物多样性保护重要区生态承载力状况,基于社会发展压力、经济发展压力、资源环境支撑力和生态弹力构建评价指标体系,利用投影寻踪模型对2008—2017年天目山－怀玉山区水源涵养与生物多样性保护重要区生态承载力进行评价。研究结果显示,第三产业占GDP比重、人均国内生产总值、一般工业固体废弃物产生量及森林覆盖率对研究区城市生态承载力有较大影响。2008年研究区城市生态承载力评价等级基本安全的城市有6个,较不安全的城市有5个,不安全的城市有2个。2017年研究区城市里生态承载力评价等级较安全的城市有1个,基本安全的城市有1个,较不安全的城市有7个,不安全的城市有4个。2008—2017年5个城市生态承载力呈上升趋势,8个城市生态承载力呈下降趋势。研究区城市生态承载力在空间分布上呈现由中心向南北递减的趋势。     

不同土壤条件下施用硝化抑制剂DMPG对葡萄生长和品质的影响

为探究在不同土壤条件下新型硝化抑制剂3,4-二甲基吡唑磷酸盐(DMPG)对鲜食葡萄生长的影响,以西昌克伦生和秦皇岛玫瑰香2个葡萄品种为研究对象,在田间试验条件下采用多点试验方法,研究DMPG对土壤养分、葡萄生长性状和品质的影响。结果表明：配施0.35%DMPG对土壤铵态氮和硝态氮含量均有显著影响,较CK处理土壤NH₄⁺-N含量增加17.58%～26.06%,NO₃^--N含量降低11.72%～27.42%;但对土壤pH、有效磷和速效钾无明显影响。DMPG处理对克伦生和玫瑰香叶绿素含量、叶面积和叶片厚度均有促进作用,与CK相比,克伦生和玫瑰香叶面积平均分别增加11.32%和9.85%,叶片厚度平均分别增加9.05%和16.22%。同时,DMPG处理可提高葡萄果实纵横径、百粒重和可溶性固形物含量,西昌克伦生3个试验点果实纵径、横径分别显著增加7.2%～11.04%、7.10%～9.82%,百粒重平均提高29.14%,而秦皇岛玫瑰香效果不显著。因此,在葡萄种植中施用DMPG能够调控土壤氮素养分,改善土壤肥力...     

我国苹果产业70年发展历程与展望

新中国成立以来,我国苹果产业经历了起步期、扩大期及平衡发展期,实现了苹果的稳定周年供应。随着时代发展,出现了苹果品种单一、平均单产低、盲目性发展、人力成本增加、新时代果农缺乏等问题,严重制约着我国苹果产业的可持续发展。根据我国国情和苹果产业发展重心,从技术提升、产业链延长、人才培养等方面提出了十点建议,以期为我国苹果产业可持续发展提供参考和帮助。     

实施保护性耕作对保护黑土带的效应

采用保护性耕作措施及其以根茬留田为主要的技术环节,论证了根茬留田的保土肥田效应。垄作少耕、根茬留田可以减轻水土流失,保护黑土层不受侵蚀,特别是干旱春季保墒效果良好,有利于一次播种保全苗,同时发挥着未腐解有机物的培肥效应;增强土壤生物活性,更新土壤中已渐老化的腐殖质,提高土壤保肥供肥性能,保持和增进地力。     

The pathology of selenium deficiency in Cyprinus carpio L

Selenium is essential for the normal life processes, and all animals, including fish, need this inorganic element. In order to research the pathology of selenium deficiency in common carp, Cyprinus carpio L., 360 juvenile carp were allocated to three treatments. Each treatment containing 120 fish was randomly divided into four groups, fed with purified diets containing selenium at 0, 0.15, 0.30 and 0.45 mg kg^?1. The results indicated that the morbidity and mortality rates of the test groups were negatively correlated with the level of selenium in the diets. The morbidity and mortality rates were, respectively, 46.7%, 33.3%, 13.3%, 0 and 26.7% 16.7%, 6.7%, 0. The affected fish exhibited pathological changes, such as ‘thin back disease’ and lordosis. Histologically, there was no abnormality observed in muscles, liver and pancreas. Ultrastructurally, there was swelling of the mitochondria of the cardiac muscle cells, the liver cells and renal tubular epithelial cells, with disintegration and lysis of the cristae of the mitochondria which vesiculated. Serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels were increased and the activity of the serum glutathione peroxidase and the serum superoxide dismutase was decreased; in contrast, the serum malonaldehyde concentration was increased.     

近江牡蛎（Crassostrea hongkongensis）家系早期发育生长比较

选取数量性状有较大差异的6个近江牡蛎（Crassostrea hongkongensis）作为亲本,成功建赢了9个半同胞家系,并对各个家系的受精、孵化、成活和早期生长的情况进行比较。结果显示,各家系子代的受精率、9孵化率和成活率均受亲本成熟度的影响;各家系的早期生长中,家系CH1、CH4和CH7的生长率大于其他家系;近江牡蛎幼虫的早期生长阶段受母本效应影响明显。     

应用RAPD标记对东方(鱼屯)属进行种类鉴别及其聚类分析

利用RAPD技术对红鳍东方、假睛东方、暗纹东方和从日本引进的红鳍东方4个种进行了遗传标记鉴别研究.在事先优化的条件下,20个随机引物共扩增出134条谱带清晰、重复性高的DNA片段,其中多态性片段77条.结果证实每一种均有其特异性扩增图谱,可作为种鉴定的依据;用UPGMA和NJ等方法进行聚类,构建的系统树与借助形态学和生化特征进行的传统分类结果一致.研究表明,RAPD作为一种新的分子标记,在海洋动物遗传鉴定方面具有巨大的潜力.     

Apparent digestibility coefficients of selected protein feed ingredients for loach Misgurnus anguillicaudatus

Apparent digestibility coefficients of dry matter, crude protein, lipid and energy, and amino acids availability in white fish meal, brown fish meal, meat meal, fermented soybean meal, soybean meal and rapeseed meal were determined for loach (Misgurnus anguillicaudatus) (12.05 ± 0.21 g), using a reference diet with 5 g kg^?1 chromic oxide and test diets that contained 700 g kg^?1 reference diet, by weight, and 300 g kg^?1 of the test feed ingredients. The juvenile loach was held in 300‐l tanks at a density of 30 fish per tank. White fish meal, brown fish meal, meat meal and fermented soybean meal had highest apparent digestibility coefficients (ADCs) of dry matter, crude protein and gross energy among ingredients tested, ranged from 50.4% to 60.9% for dry matter, from 64.6% to 88.4% for crude protein and from 57.9% to 79.0% for gross energy. The apparent digestibility coefficients of dry matter ranged from 61.0% to 66.9% for animal products and 50.4% to 60.7% for plant products. For crude protein, apparent digestibility coefficients of protein exceeding 80% were observed for white fish meal, brown fish meal, meat meal and fermented soybean meal, and the apparent digestibility coefficients of protein in rapeseed meal were the lowest among all the treatments. Lipids from both animal and plant feedstuffs were poorly digested by loach, ranging from 64.0% to 77.6%. The apparent digestibility coefficients of energy were similar to those of dry matter and protein, and the highest and lowest ADCs of energy were found in WFM and RM, respectively. The loach used dietary phosphorus from the animal feedstuffs more efficiently than from plant feedstuffs (soybean meal and rapeseed meal), with ADC‐values ranging from 42.3% to 53.1% and from 25.1% to 32.7%, respectively. For the animal products, the availabilities of amino acids in white fish meal and brown fish meal were higher than that in meat meal, expect for Met, Asp, Pro, Gly, and Cys. Among all the plant products, the availabilities of amino acids in fermented soybean meal were higher than in soybean meal and rapeseed meal, and thus had a greater potential to be used as a dietary replacement of fish meal in loach diets.     

福建省平鳍鳅科鱼类的研究

经鉴定,采自福建省龙岩市九江支流满竹溪的拟腹吸鳅属标本为一新种,依山名而定为梅花山拟腹吸鳅Ｐｓｅｕｄｏｇａｓｔｒｏｍｙｚｏｎ ｍｅｉｈｕａｓｈａｎｅｎｉｓｉ ｓｐ．ｎｏｖ。根据三年野外调查和鱼类标本采集,已知福建省平鳍鳅科鱼类计１８种。